Retractable cutting and pulling tool with uphole milling capability

Abstract

Cutter blades extend and stay extended as long as pressure on a piston is continued. The blades either open fully in open hole or cut through the wall of a tubular and then mill in an uphole direction to take out a piece of the tubular. The piston that held out the blades when pressure was applied is acted on by a return bias when the pressure is removed so that the blades can retract and the tool removed through the cut tubular. As a backup a plug can be dropped to obstruct a through passage in the piston so that pressure from the surface can be used to force the piston back to retract the blades. Continued drilling operations or the cut and milled portion can be then blocked off such as with cement for a plug and abandonment of the well.

We claim: 
     
       1. A cut and tubular sectioning apparatus for a subterranean tubular comprising:
 a mandrel having an open mandrel passage extending between an upper and a lower end for flow therethrough; 
 a piston movably mounted to said mandrel; 
 at least one blade in a blade assembly hydraulically responsive to piston movement resulting from flow in said passage from said upper toward said lower end of said passage for pivoting extension and retraction with respect to the subterranean tubular for respectively cutting through a wall of the tubular and sectioning the tubular in an uphole direction and removal of a severed section of the tubular while supported on said blade assembly for removal of the severed section of the tubular with the apparatus in a continuation of the uphole movement of said blade assembly after said cutting through and sectioning the tubular; 
 said at least one blade pivoting to full extension before cutting through the wall that has a smaller diameter than an outer dimension of said at least one blade, said blade beginning cutting through the wall in the fully extended position to position said fully extended blade below a smaller dimension of the subterranean tubular for removal thereof. 
 
     
     
       2. The apparatus of  claim 1 , wherein:
 said piston has a passage therethrough and is driven in a first direction for extension of said blade assembly by flow through said passage. 
 
     
     
       3. The apparatus of  claim 2 , wherein:
 reduction of said flow allows said piston to move in a second direction opposite said first direction for removal through the tubular being cut. 
 
     
     
       4. The apparatus of  claim 1 , wherein:
 said piston is moved in a first direction so that said blade assembly is extended by flow through a piston passage that is in flow communication with said mandrel passage, said mandrel further comprising a flow restriction to create back pressure against a lower end of said piston. 
 
     
     
       5. The apparatus of  claim 1 , wherein:
 said blade assembly pivots about a stationary pivot location on said mandrel. 
 
     
     
       6. The apparatus of  claim 3 , wherein:
 said piston is biased in said second direction. 
 
     
     
       7. The apparatus of  claim 1 , wherein:
 said piston is driven in a reverse direction than flow that passes through a piston passage for extension of said blade assembly. 
 
     
     
       8. The apparatus of  claim 1 , wherein:
 said piston comprises a piston passage that is selectively obstructed so that pressure on said piston with said piston passage obstructed retracts said blade assembly. 
 
     
     
       9. The apparatus of  claim 1 , wherein:
 said mandrel further comprises a centralizer. 
 
     
     
       10. The apparatus of  claim 6 , wherein:
 said bias is provided by a mechanical or fluid spring. 
 
     
     
       11. The apparatus of  claim 10 , wherein:
 said piston is moved in a first direction so that said blade assembly is extended by flow through a piston passage that is in flow communication with said mandrel passage, said mandrel further comprising a flow restriction to create back pressure against a lower end of said piston. 
 
     
     
       12. The apparatus of  claim 11 , wherein:
 said blade assembly pivots about a stationary pivot location on said mandrel. 
 
     
     
       13. The apparatus of  claim 12 , wherein:
 said piston is driven in a reverse direction than flow that passes through said piston passage for extension of said blade assembly. 
 
     
     
       14. The apparatus of  claim 13 , wherein:
 said piston passage is selectively obstructed so that pressure on said piston with said piston passage obstructed retracts said blade assembly. 
 
     
     
       15. The apparatus of  claim 14 , wherein:
 said mandrel further comprises a centralizer. 
 
     
     
       16. The apparatus of  claim 8 , wherein:
 said passage is selectively obstructed by a dart that lands on a seat surrounding said piston passage. 
 
     
     
       17. The apparatus of  claim 14 , wherein:
 said passage is selectively obstructed by a dart that lands on a seat surrounding said piston passage. 
 
     
     
       18. The apparatus of  claim 10 , wherein:
 said mechanical spring comprises a coiled spring or a stack of Belleville washers. 
 
     
     
       19. The apparatus of  claim 1 , wherein:
 said blade assembly comprises blades having a top surface cutting structure that when extended facilitate sectioning the tubular in an uphole direction.